Toshiba TLCS-900/H1 Series Data Book page 325

3.14.3.3 Display memory mapping and Panning Function (Common spec. SR and TFT)
LCDC can change the panel window if only you change each start address of A, B and C
area. Display area can be vertical and horizontal panned by changing row and column
address.
This LCDC can select many display mode: 1bpp(monochrome), 2bpp(4gray), 3bpp(8gray),
4bpp(16gray), 8bpp(256 color) and 12bpp(4096 color) and 1-line(row) data volume is different
each display mode. If use panning function, it need to care and calculate address each
display mode. As Details, refer the follows page "Relation of Memory map image and Output
data". And this LCDC can support external SDRAM, SRAM and internal SRAM for display
RAM.
When you use SDRAM for display RAM, data from one line to the next line cannot be input
continuously in display RAM, even if you don't use the panning function. One Row address of
display SDRAM corresponds to 1'st line of display panel. Now display data of 2'nd line cannot
be set within the 1'st row address of display RAM even if the necessary data for the size you
want to display do not fill the capacity of 1'st row address of display SDRAM. Adding the one
line to display panel is equal to adding one address to row address of display SDRAM. In
other words, when using SDRAM for display RAM, address calculation for panning is easy.
When you use SRAM for display RAM, data from one line to the next line must be input
continuously in display RAM. But address calculation for panning is complex and horizontal
panning function is not support.
3.14.3.4 Data transmission
TMP91CH21 has LD bus(LD7 to LD0): special data bus for LCDD. And about that bus width can
support 4, 8bit and each bus width can select 2 formats. 2 type formats of 8bit bus width can
support only STN color mode (256, 4096 color). 12bit bus width is supported only TFT mode.
And LD bus data invert function is supported. By setting LCDMODE2<LDINV>=1, All LD bus
data invert. There is <AUTOINV>bit in this LCDMODE2 register, but this automatic data invert
function is for only TFT mode.
Under Development
92CH21-321
TMP92CH21